The Questionable Link Between Saturated Fat and Heart Disease

Are butter, cheese and steak really bad for you? The dubious science behind the anti-fat crusade

"Saturated fat does not cause heart disease"—or so concluded a big study published in March in the journal Annals of Internal Medicine. How could this be? The very cornerstone of dietary advice for generations has been that the saturated fats in butter, cheese and red meat should be avoided because they clog our arteries. For many diet-conscious Americans, it is simply second nature to opt for chicken over sirloin, canola oil over butter.

The new study's conclusion shouldn't surprise anyone familiar with modern nutritional science, however. The fact is, there has never been solid evidence for the idea that these fats cause disease. We only believe this to be the case because nutrition policy has been derailed over the past half-century by a mixture of personal ambition, bad science, politics and bias.

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Our distrust of saturated fat can be traced back to the 1950s, to a man named Ancel Benjamin Keys, a scientist at the University of Minnesota. Dr. Keys was formidably persuasive and, through sheer force of will, rose to the top of the nutrition world—even gracing the cover of Time magazine—for relentlessly championing the idea that saturated fats raise cholesterol and, as a result, cause heart attacks.

This idea fell on receptive ears because, at the time, Americans faced a fast-growing epidemic. Heart disease, a rarity only three decades earlier, had quickly become the nation's No. 1 killer. Even President Dwight D. Eisenhower suffered a heart attack in 1955. Researchers were desperate for answers.

As the director of the largest nutrition study to date, Dr. Keys was in an excellent position to promote his idea. The "Seven Countries" study that he conducted on nearly 13,000 men in the U.S., Japan and Europe ostensibly demonstrated that heart disease wasn't the inevitable result of aging but could be linked to poor nutrition.

Critics have pointed out that Dr. Keys violated several basic scientific norms in his study. For one, he didn't choose countries randomly but instead selected only those likely to prove his beliefs, including Yugoslavia, Finland and Italy. Excluded were France, land of the famously healthy omelet eater, as well as other countries where people consumed a lot of fat yet didn't suffer from high rates of heart disease, such as Switzerland, Sweden and West Germany. The study's star subjects—upon whom much of our current understanding of the Mediterranean diet is based—were peasants from Crete, islanders who tilled their fields well into old age and who appeared to eat very little meat or cheese.

As it turns out, Dr. Keys visited Crete during an unrepresentative period of extreme hardship after World War II. Furthermore, he made the mistake of measuring the islanders' diet partly during Lent, when they were forgoing meat and cheese. Dr. Keys therefore undercounted their consumption of saturated fat. Also, due to problems with the surveys, he ended up relying on data from just a few dozen men—far from the representative sample of 655 that he had initially selected. These flaws weren't revealed until much later, in a 2002 paper by scientists investigating the work on Crete—but by then, the misimpression left by his erroneous data had become international dogma.

In 1961, Dr. Keys sealed saturated fat's fate by landing a position on the nutrition committee of the American Heart Association, whose dietary guidelines are considered the gold standard. Although the committee had originally been skeptical of his hypothesis, it issued, in that year, the country's first-ever guidelines targeting saturated fats. The U.S. Department of Agriculture followed in 1980.

Other studies ensued. A half-dozen large, important trials pitted a diet high in vegetable oil—usually corn or soybean, but not olive oil—against one with more animal fats. But these trials, mainly from the 1970s, also had serious methodological problems. Some didn't control for smoking, for instance, or allowed men to wander in and out of the research group over the course of the experiment. The results were unreliable at best.

But there was no turning back: Too much institutional energy and research money had already been spent trying to prove Dr. Keys's hypothesis. A bias in its favor had grown so strong that the idea just started to seem like common sense. As Harvard nutrition professor Mark Hegsted said in 1977, after successfully persuading the U.S. Senate to recommend Dr. Keys's diet for the entire nation, the question wasn't whether Americans should change their diets, but why not? Important benefits could be expected, he argued. And the risks? "None can be identified," he said.

In fact, even back then, other scientists were warning about the diet's potential unintended consequences. Today, we are dealing with the reality that these have come to pass.

One consequence is that in cutting back on fats, we are now eating a lot more carbohydrates—at least 25% more since the early 1970s. Consumption of saturated fat, meanwhile, has dropped by 11%, according to the best available government data. Translation: Instead of meat, eggs and cheese, we're eating more pasta, grains, fruit and starchy vegetables such as potatoes. Even seemingly healthy low-fat foods, such as yogurt, are stealth carb-delivery systems, since removing the fat often requires the addition of fillers to make up for lost texture—and these are usually carbohydrate-based.

The problem is that carbohydrates break down into glucose, which causes the body to release insulin—a hormone that is fantastically efficient at storing fat. Meanwhile, fructose, the main sugar in fruit, causes the liver to generate triglycerides and other lipids in the blood that are altogether bad news. Excessive carbohydrates lead not only to obesity but also, over time, to Type 2 diabetes and, very likely, heart disease.

The real surprise is that, according to the best science to date, people put themselves at higher risk for these conditions no matter what kind of carbohydrates they eat. Yes, even unrefined carbs. Too much whole-grain oatmeal for breakfast and whole-grain pasta for dinner, with fruit snacks in between, add up to a less healthy diet than one of eggs and bacon, followed by fish. The reality is that fat doesn't make you fat or diabetic. Scientific investigations going back to the 1950s suggest that actually, carbs do.

The second big unintended consequence of our shift away from animal fats is that we're now consuming more vegetable oils. Butter and lard had long been staples of the American pantry until Crisco, introduced in 1911, became the first vegetable-based fat to win wide acceptance in U.S. kitchens. Then came margarines made from vegetable oil and then just plain vegetable oil in bottles.

All of these got a boost from the American Heart Association—which Procter & Gamble, the maker of Crisco oil, coincidentally helped launch as a national organization. In 1948, P&G made the AHA the beneficiary of the popular "Walking Man" radio contest, which the company sponsored. The show raised $1.7 million for the group and transformed it (according to the AHA's official history) from a small, underfunded professional society into the powerhouse that it remains today.

After the AHA advised the public to eat less saturated fat and switch to vegetable oils for a "healthy heart" in 1961, Americans changed their diets. Now these oils represent 7% to 8% of all calories in our diet, up from nearly zero in 1900, the biggest increase in consumption of any type of food over the past century.

This shift seemed like a good idea at the time, but it brought many potential health problems in its wake. In those early clinical trials, people on diets high in vegetable oil were found to suffer higher rates not only of cancer but also of gallstones. And, strikingly, they were more likely to die from violent accidents and suicides. Alarmed by these findings, the National Institutes of Health convened researchers several times in the early 1980s to try to explain these "side effects," but they couldn't. (Experts now speculate that certain psychological problems might be related to changes in brain chemistry caused by diet, such as fatty-acid imbalances or the depletion of cholesterol.)

We've also known since the 1940s that when heated, vegetable oils create oxidation products that, in experiments on animals, lead to cirrhosis of the liver and early death. For these reasons, some midcentury chemists warned against the consumption of these oils, but their concerns were allayed by a chemical fix: Oils could be rendered more stable through a process called hydrogenation, which used a catalyst to turn them from oils into solids.

From the 1950s on, these hardened oils became the backbone of the entire food industry, used in cakes, cookies, chips, breads, frostings, fillings, and frozen and fried food. Unfortunately, hydrogenation also produced trans fats, which since the 1970s have been suspected of interfering with basic cellular functioning and were recently condemned by the Food and Drug Administration for their ability to raise our levels of "bad" LDL cholesterol.

Yet paradoxically, the drive to get rid of trans fats has led some restaurants and food manufacturers to return to using regular liquid oils—with the same long-standing oxidation problems. These dangers are especially acute in restaurant fryers, where the oils are heated to high temperatures over long periods.

The past decade of research on these oxidation products has produced a sizable body of evidence showing their dramatic inflammatory and oxidative effects, which implicates them in heart disease and other illnesses such as Alzheimer's. Other newly discovered potential toxins in vegetable oils, called monochloropropane diols and glycidol esters, are now causing concern among health authorities in Europe.

In short, the track record of vegetable oils is highly worrisome—and not remotely what Americans bargained for when they gave up butter and lard.

Cutting back on saturated fat has had especially harmful consequences for women, who, due to hormonal differences, contract heart disease later in life and in a way that is distinct from men. If anything, high total cholesterol levels in women over 50 were found early on to be associated with longer life. This counterintuitive result was first discovered by the famous Framingham study on heart-disease risk factors in 1971 and has since been confirmed by other research.

Since women under 50 rarely get heart disease, the implication is that women of all ages have been worrying about their cholesterol levels needlessly. Yet the Framingham study's findings on women were omitted from the study's conclusions. And less than a decade later, government health officials pushed their advice about fat and cholesterol on all Americans over age 2—based exclusively on data from middle-aged men.

Sticking to these guidelines has meant ignoring growing evidence that women on diets low in saturated fat actually increase their risk of having a heart attack. The "good" HDL cholesterol drops precipitously for women on this diet (it drops for men too, but less so). The sad irony is that women have been especially rigorous about ramping up on their fruits, vegetables and grains, but they now suffer from higher obesity rates than men, and their death rates from heart disease have reached parity.

Seeing the U.S. population grow sicker and fatter while adhering to official dietary guidelines has put nutrition authorities in an awkward position. Recently, the response of many researchers has been to blame "Big Food" for bombarding Americans with sugar-laden products. No doubt these are bad for us, but it is also fair to say that the food industry has simply been responding to the dietary guidelines issued by the AHA and USDA, which have encouraged high-carbohydrate diets and until quite recently said next to nothing about the need to limit sugar.

Indeed, up until 1999, the AHA was still advising Americans to reach for "soft drinks," and in 2001, the group was still recommending snacks of "gum-drops" and "hard candies made primarily with sugar" to avoid fatty foods.

Our half-century effort to cut back on the consumption of meat, eggs and whole-fat dairy has a tragic quality. More than a billion dollars have been spent trying to prove Ancel Keys's hypothesis, but evidence of its benefits has never been produced. It is time to put the saturated-fat hypothesis to bed and to move on to test other possible culprits for our nation's health woes.

Ms. Teicholz has been researching dietary fat and disease for nearly a decade. Her book, "The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet," will be published by Simon & Schuster on May 13.

my husband and I have switched to using only home rendered animal fat to cook with almost a year. its cheap and fairly easy to do. so far our sons cystic acne , and mine and my daughters skin conditions have dissipated. getting rid of veg. oil was the only thing we changed. it makes sense , we believe.

Don't forget psychology as well. The oral fixation is running amok. Notice how the decline in the populace's smoking has also correlated with increase in obesity and chronic babbling on cell phones? The unweaned infantile "adults" sure do like to stick stuff in their mouths.

This history of low-fat diets for heart disease has many parallels to the history of psychotherapy for brain/mental illnesses. Both were widely promoted in the 20th century by power hungry doctors (Dr. Keys and Freud) obtaining influence with powerful organizations, who in turn widely promoted their theories (with the help of money and politics) until their unproven theories started to seem like common sense. Under the influence of these unfounded theories promoted by parties with a financial/political stake in them, people made choices that caused more harm than good — they replaced healthy diets with unhealthy diets, and healthy authentic friendships with unhealthy paid therapists. We’ve damaged the quality of our diets and our relationships to one another, and consequently we’ve damaged our physical and emotional health.

I hope that we learn from these mistakes, and don’t repeat them, and that we learn to look carefully at the evidence and act accordingly.

'"Saturated fat does not cause heart disease"—or so concluded a big study published in March in the journal Annals of Internal Medicine.' ~ Nina Teicholz

Not so. The study concluded that, 'Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats.' [1]

No, but you can look at the massive amount of research going back to Weston Price etc. The American diet nearly destroyed my health. Now I eat farm eggs, grass fed beef, wild salmon, fruits, and vegetables and my medical test numbers are FABULOUS. My doctors said, "Don't stop doing what you are doing!"

The elephant in the room here (no pun intended) is the fact that NO ONE mentions the lack of exercise in anyone's daily life, and/or feels the need to tie these two together: calorie CONSUMPTION with calorie burning.

Fact is that this country went from a nation of farmers to a nation of office workers and iPod players, etc. Kind of hard to dispute the fact that you MUST burn more calories than you consume.

Exactly. Dr. Adkins nailed it. He has been proven correct time and again, and his ideas continue to be bastardized and imitated by other diets, e.g., the "Mediterranean Diet." But it was Adkins who was correct all along, even though others in medicine mocked his ideas.

Russ, if she lived to be 106 (unless that's a typo), then how can you possibly know that the doctors were "right," as you indicate? Think about it. 106 is actually pretty old. She may well have died of "natural consequences" having nothing to do with her regular consumption of eggs. Of course, if an autopsy had concluded that the eggs were the cause of death (e.g., because of salmonella or something that could be linked conclusively to the eggs), then you would have strong basis for saying that the "doctors were right." Absent that, I'm skeptical.

No offense to this author, but I think I'll follow the recommendation of my cardiologist, the American Heart Association, and just about every other respectable fact-based study that suggests limiting saturated fat intake is one of the primary ways one can reduce the risk of having heart disease.

I totally believe this. My father has ate eggs, bacon, and eggs religiously followed by more healthier lunch and dinner just like the article says. He is in the best shape of most of our family members that stay away from those foods but base their diet on carbs!

I wish people would stop publishing incorrect facts, because it can have unintended and serious impacts. When I emigrated to the US, instead of following my mom's advice, I started following the low-fat diet as recommended by the US, so called specialists. I attribute the low-fat diet to vitamin-d deficiencies and other health issues, that took significant time and effort to resolve. Charlatans that provide incorrect medical advice can be sued and so should so called dietitians and scientists, because a bad diet inevitably leads to disease.

How can Ms. Teicholz throw out decades of overwhelming research recommending limiting saturated fat consumption in favor of one new study that has generated strong criticism from expert health professionals? As a registered dietitian working with the National Association for Margarine Manufacturers I must say that that encouraging Americans to change from a balanced diet to one that contradicts a mainstream, science-backed diet is bad practice.

Earlier this year, the American Butter Institute released data showing butter consumption at a 40 year high, up 25% or 1.4 pounds per capita in just the past decade. That translates to an additional half pound of saturated fat every year for every man, woman and child in the U.S. The current average of saturated fat intake is about 11 percent of total calories consumed. Just last year, the American Heart Association College of Cardiology issued guidelines that recommend limiting saturated fat intake to 5 to 6 percent of the total.

Americans need to replace foods high in saturated fats like butter with soft spread margarines. Margarine companies have removed all the partially hydrogenated oil, the source of trans fat, from branded soft spread margarines. Soft spread margarine has 2 grams or less saturated fat per serving compared to butter’s 7 grams.

Consumers have a choice between years of scientific research recommending reduced consumption of saturated fat or one study to the contrary.

This is probably the most interesting article I've read in a while. Always wondered why nations that don't hold back on the "dangerous fats" like butter and ghee are actually fitter than Americans. Will buy the book.

Another study refuting another study! Does everyone really believe all of these studies mindlessly reported every day in the press?. Do reporters even read them or do they just rewrite the press releases and call the usual sources for comments? It won't be long before another study relinks saturated fat with heart disease.

Mediterranean Diet for most is the best! It seems to me that we need to have "bad" foods and "good" foods. I say all whole foods are good and should be eaten. There is enough evidence based on the type of digestive tract we have and our combination of teeth that we were meant to be omnivores. Is it possible to be a vegan and in great health? Sure. But it's also possible to be a vegan in lousy health. Haven't you noticed that some of the most chronically ill people are the ones eating only the coconuts and bean sprouts? As far as animal protein and saturated fats it's best to consume in moderate portions. The diet should be highest in fresh vegetables. And don't forget to drink 2-3 liters of water per day.

Its all absolutely true. For years I gained weight eating the 'food pyramid/plate' carb heavy diet. I ate my whole grains and my calorie laden juices, avoided meats and fats, etc. I was even on a strict low/no fat vegan diet for several years. Honestly, I felt lousy, couldn't lose weight even though I worked out like crazy, I always felt hungry. I had an accident that took me a few years to recover from during which I gained another 40lbs, putting me smack in the morbidly obese category. I developed diabetes, high blood pressure and high cholesterol. Still I tried eating my 'healthy' whole grains and wore out juice machines, keeping myself under 2000 calories and still working out. And I kept gaining weight.

So clearly this strategy didn't work, and I read all the dietary information and studies that were its foundation. Like the author of this story describes, the studies were awful. They asked people what they ate (largely lies or poor recollection), threw out huge swaths of data they didn't like, claimed to compensate for the cancer causing effects of smoking and poor exercise habits, and leaped to conclusions with little more than poor correlation.

So I made up my own diet looking for nutritionally dense foods, and after watching "survivorman" I adopted his in-the-wild diet. Eggs, meat where it could be hunted or trapped, fish, berries and other whole fruit, green leafy things and shoots, occasionally a root or tuber left in a campfire to roast. I kept myself to the same ~2000 calories and did nothing else but walk 2-3 miles a day with the dog.

I lost 100lbs in six months. My diabetes and high blood pressure went away. My blood work is now perfectly pristine. My LDL cholesterol dropped to within 1 point of what is considered the healthy minimum. I have energy, I sleep better, I feel great. I'm never hungry. I never feel deprived.

How did all this bad information come to be and stick with us so long? Aside from the authors comments on that, research people want more grant money to do more research. Startling and interesting results get more grants. A scattergram of information all over the place with no clear result gets nothing. In all my life I've never seen a doctor admit they'd made a mistake or that they were wrong. And the press wants readers and eyeballs, so pushing a study that barely establishes correlation and using words like 'linked' and 'shown to cause' is much more interesting than "this might have some connection, but this study doesn't really show anything". Not to mention, a cracker made out of corn and wheat and boiled in soybean oil tastes good, is dirty cheap to make, its highly profitable and has a long shelf life. Raising animals is expensive, a huge hassle, its barely profitable and the shelf life is short. As a recent president said "We're pretty good at growing corn!".

Ancel Keys became famous for his dietary pronouncements the year before I graduated from medical school in 1962. Since that moment over fifty years ago we have had an unending riot of food fads and fallacies. When I chose Internal Medicine for my line of work it became necessary for me to learn all of that material. From the very beginning I smelled a rat. Actually several rats. The recommendations were always changing for various diseases and the recommendations did not correspond to the Biochemistry and Physiology I was learning. It began to seem that people were out to make some bucks by confusing and defrauding the American people.

Let me describe two that are current and are defrauding tens of millions of Americans right now. The first is the distinguished committee that meets every few years to revise the definition of Diabetes Mellitus. (You might think the definition of diabetes would remain the same. Not when there are drugs to be sold) For the first time in the history of medicine a new disease category has been created in which all of those categorized are completely normaal. It is called Prediabetes. This group includes the many tens of millions of Americans who have fasting blood sugars beween 101-120. This is an egregous fraud because none of these people are ill and very few are likely to develop diabetes. There is no such thing as Prediabetes.

Finally, there are the "normal" values for cholesterol which are revised downward every ten years, creating millions of new sick people who need to take statins. This year the cholesterol committee has outdone itself. Under the new guidelines you have an abnormal cholesterol which should be treated if you are between the ages of 40 and 75 and the risk of your having a heart attack in the next ten years is greater than 7.5%. That's right, a risk of 7% is good and one of 8% is bad. It is completely impossible to determine such risks, but the committee would have you believe that they are so precise that they can determine risk within 0.5%. The committees which set the guidelines for Diabetes and Hypercholesterolemia lost any credibility they may have had many years ago.

"Are you stupid or something?" ("Forest Gump"). He was being sarcastic, or maybe sardonic or ironic! He meant the opposite, that she in fact lived to a very old age eating eggs! He did NOT mean the eggs killed her!Sheesh... Terrible reading comprehension!!!!!

They are basing their information on flawed, outdated data. The AHA and your cardiologist have based their livelihoods, careers, and reputations on what many consider to be incorrect. How likely is it you think that they will admit they are wrong.

Both my husband and my numbers were terrible for 30 years on that diet. We switched to paleo eating (eggs, meat, fish, vegetables, fruit, nothing processed, olive oil) and ALL the numbers improved for the first time in decades. It has now been three years. Our doctors are stunned and said DON'T stop the paleo diet.

The American diet has lead to astonishing levels of obesity. People 's bodies are no longer fat-burning machines as they were designed to be. Overloaded on carbs, they wreck their insulin systems. TONS of research proves this. As the article said, the French etc on animal fat diets were not obese like Americans are now.

We eat PLENTY of fruits and vegetables so this is NOT a no or low carb diet. It is a REASONABLE carb diet. Humans were not meant to live on grains, high fructose corn syrup, etc.and the obesity epidemic proves it.

Everyone is different. You are doing fine on the standard diet. My husband and I were fat, tired and sick, despite leading active lives and eating "well."

Of course, all those "experts" you cite, Mr. Fischio, have an enormous amount to gain from your (and everyone else's) continued "enthrallment" with their every utterance.

Both sets of my grandparents lived to be in their mid-80s -- every single one of them would have scoffed at the "saturated fat, trans-fat, nitrate, sodium, Styrofoam, Liberal-worshiping, gay-marriage-worshiping, CO2 fearful, witch-burning paranoiah, as it stands today.

But then, they lived and ENJOYED their lives. How far we keep "devolving" as a species. Well, keep voting for "progressives" -- you haven't seen anything yet.

I had a very similar experience. I lost 30 pounds, my cholesterol is normal (no medication), I have more energy, gout and other joint pain is also gone. I get some sugar from dry hard cider and wine, but I quit beer and sweet drinks. I have no juice, berries and fruit in moderation. I eat meats of all kinds and lots of salads and vegetables. For breakfast I have eggs and bacon/sausage.

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